A digital camera system includes a print medium having a printing area and a magnetically-sensitive area, and a digital camera. The digital camera includes a photo-width printhead for printing digital images on the printing area of the print medium, and a magnetic recorder for recording information associated with the digital images on the magnetically-sensitive area of the print medium at the same time as the printhead prints the associated digital images onto the printing area.

Claim:

I claim:

1. A digital camera system comprising: (A) a print medium having a printing area and a magnetically-sensitive area; (B) a digital camera comprising: a photo-width printhead forprinting digital images on the printing area of the print medium; and a magnetic recorder for recording information associated with said digital images on the magnetically-sensitive area of the print medium at the same time as the printhead prints theassociated digital images onto the printing area.

2. The digital camera system of claim 1, wherein the associated information comprises audio information associated with the digital image.

3. The digital camera system of claim 1, wherein said digital camera further comprises a microphone for recording audio information.

4. The digital camera system of claim 1, wherein the print medium is detachably stored in the digital camera.

5. A digital camera as claimed in claim 1 wherein said printing area and said magnetically-sensitive area are on opposite faces of the print medium.

Description:

FIELD OF THE INVENTION

The present invention relates to the field of digital image cameras and in particular, discloses a Camera and Media for Art Prints or Photos with Magnetically Recordable Feature.

BACKGROUND OF THE INVENTION

The preferred embodiment is preferably implemented through modification of a hand held camera device such as that described in patent application U.S. Ser. No. 09/113,060, which claims priority from Australian provisional application No.PO7991 entitled "Image Processing Method and Apparatus" (Art 01) filed 15 July, 1997.

The aforementioned patent specification discloses a camera system, hereinafter known as an "Artcam" type camera, wherein sensed images can be directly printed out by an Artcam portable camera unit. Further, the aforementioned specificationdiscloses means and methods for performing various manipulations on images captured by the camera sensing device leading to the production of various effects in any output image. The manipulations are disclosed to be highly flexible in nature and can beimplemented through the insertion into the Artcam of cards having encoded thereon various instructions for the manipulation of images, the cards hereinafter being known as Artcards. The Artcam further has significant onboard processing power in anArtcam Central Processor unit (ACP) which is interconnected to a memory device for the storage of important data and images.

The Artcam camera system which a digital camera with an inbuilt integral color printer. Additionally, the camera provides hardware and software for the increasing of the apparent resolution of the image sensing system and the conversion of theimage to a wide range of "artistic styles" and a graphic enhancement.

In one aspect, the Artcam camera system comprises at least one area image sensor for imaging a scene, a camera processor means for processing said imaged scene in accordance with a predetermined scene transformation requirement, a printer forprinting out said processed image scene on print media, print media and printing ink stored in a single detachable module inside said camera system, said camera system comprising a portable hand held unit for the imaging of scenes by said area imagesensor and printing said scenes directly out of said camera system via said printer.

Preferably the camera system includes a print roll for the storage of print media and printing ink for utilization by the printer, the print roll being detachable from the camera system. Further, the print roll can include an authenticationchip containing authentication information and the camera processing means is adapted to interrogate the authentication chip so as to determine the authenticity of said print roll when inserted within said camera system.

Further, the printer can include a drop on demand ink jet printer and guillotine means for the separation of printed photographs.

With such an arrangement, it would be desirable to be able to record ancillary information with each output photograph.

SUMMARY OF THE INVENTION

It is an object of the present invention to provide for the magnetic recording of information such as audio with a photo output by an Artcam device.

In accordance with a first aspect of the present invention, there is provided a camera system for the creation of images, the camera system comprising a sensor for sensing an image; a processing means for processing the sensed image inaccordance with predetermined processing requirements; a printer means for printing the sensed image on the surface of print media, the print media including a magnetically sensitive surface; a magnetic recording means for recording associatedinformation on the magnetically sensitive surface.

The associated information can comprise audio information associated with the sensed image and the printer means preferably prints the sensed image on a first surface of the print media and the magnetic recording means records the associatedinformation on a second surface of the print media. The print media can be stored on an internal detachable roll in the camera system. In one embodiment, the magnetic sensitive surface can comprise a strip affixed to the back surface of the printmedia.

In accordance with a second aspect of the present invention, there is provided a camera system for recording images, said camera system comprising:

an electronic image sensor for sensing an image;

a digital processing means for processing said sensed image in accordance with predetermined processing requirements; a photo width ink jet printer means for printing said processed image on a surface of ink jet print media, said ink jet printmedia including a magnetic recording surface; a magnetic recording means for recording associated information on said magnetic recording surface.

Preferably, the printer means prints said sensed image on a first surface of said print media and the magnetic recording means records said associated information on a second surface of said print media. Preferably, said first and said secondsurfaces are on different faces of said print media.

Preferably, said ink jet print media is stored on an internal detachable roll in said camera system, said camera system comprising a hand held portable camera device, said photo width ink jet printer being built into said hand held portablecamera device.

BRIEF DESCRIPTION OF THE DRAWINGS

Notwithstanding any other forms which may fall within the scope of the present invention, preferred forms of the invention will now be described, by way of example only, with reference to the accompanying drawings in which:

FIG. 1 illustrates schematically the camera system constructed in accordance to the preferred embodiment;

FIG. 3 illustrates a format of the magnetic strip on the back of the photo;

FIG. 4 illustrates a reader device utilized to read data recorded on the back of a photograph; and

FIG. 5 illustrates the utilization of an apparatus of the preferred embodiment.

DESCRIPTION OF PREFERRED AND OTHER EMBODIMENTS

In the preferred embodiment a magnetic sensitive print media material is utilized for the recording of an audio message on the back of an output photograph. The Artcam device is altered so as to include a magnetic recording device which cancomprise an array of magnetic recorders covering a whole surface of the photograph or alternatively, a magnetic strip can be provided wherein, for example, a central portion of the photograph is magnetically sensitive. The Artcam devices are furtherprovided with the ability to record an audio message for later playback.

The preferred embodiment is preferably implemented through suitable programming of a hand held camera device such as that described in Australian Provisional Patent Application No. PO7991 U.S. Ser. No. 09/113,060) entitled "Image ProcessingMethod and Apparatus (Art 01)" filed 15 Jul., 1997.

The aforementioned patent specification discloses a camera system, hereinafter known as an "Artcam" type camera, wherein sensed images can be directly printed out by an Artcam portable camera unit. Further, the aforementioned specificationdiscloses means and methods for performing various manipulations on images captured by the camera sensing device leading to the production of various effects in any output image. The manipulations are disclosed to be highly flexible in nature and can beimplemented through the insertion into the Artcam of cards having encoded thereon various instructions for the manipulation of images, the cards hereinafter being known as Artcards. The Artcam further has significant onboard processing power by anArtcam Central Processor unit (ACP) which is interconnected to a memory device for the storage of important data and images.

In the preferred embodiment, the Artcam device is suitably modified so as to equip it with a microphone device and associated recording technologies. When a picture is taken, the opportunity is provided to record either the surrounding soundenvironment or a message associated with the image. The print media or film is pretreated so as to make it magnetically sensitive in a similar manner to that provided by tape media. The recording can be over the whole back surface of the output photoor alternatively a magnetically sensitive strip may be provided. The recorded audio is stored on the back of the output photograph in an encoded format, the encoding preferably being of a highly digital resilient form. The recorded audio provides apermanent audio record associated with the corresponding photograph. Subsequently, a playback apparatus is provided for scanning the encoded audio and decoding this information.

Turning now to FIG. 1, there is illustrated, in schematic form the preferred embodiment 1 which includes the arrangement as described in the aforementioned patent specification wherein an image 2 is sensed via a CCD sensor 3 and forwarded to anArtcam central processor 4 which includes significant computational resources as described in the aforementioned patent specification. The Artcam central processor 4 can store the image in memory 5 which preferably comprises a high speed RAMBUS (TradeMark) interfaced memory. The Artcam central processor 4 is also responsible for controlling the operation of a printhead 6 for the printing out of full colour photographs, eg. 7, so as to provide for instant images on demand in addition to the magneticrecording head 16, for recording on the back of the photo.

In the preferred embodiment, the camera arrangement 1 is also supplied with a sound chip 10 which interfaces via RAMBUS bus 11 to memory 5 under the control of the ACP processor 4. The sound chip 10 can be of a standard or specialised form andcan, for example, comprise a DSP processor that takes an analogue input 12 from a sound microphone 13. Alternatively, with increasing chip complexities (Moore's Law), the functionality of sound chip 10 can be incorporated onto the ACP chip 4 whichpreferably comprises a leading edge CMOS type integrated circuit chip. It will be readily evident that many other types of arrangements can be provided which fall within the scope of the present invention.

The sound chip 10 converts the analogue input 12 to a corresponding digital form and forwards it for storage in memory 5. The recording process can be activated by means of the depressing of a button (not shown) on the camera device, the buttonbeing under the control of the ACP processor 4 otherwise it can be substantially automatic when taking a photo. The recorded data is stored in the memory 5.

Turning now to FIG. 2, the camera arrangement preferably includes a printer device 6 such as an ink jet printer which includes a printhead 6 to print an image on compatible print media 17 and a magnetic recording head 16. A further printheadcan be used to print information on the back of print media 17. Similar arrangements for printing information on the back of an output photo image are described in U.S. Ser. No. 09/112,741 (Art 12) the contents of which are hereby incorporated bycross reference.

Turning now to FIG. 3, there is illustrated an example of a magnetic strip 18 formed on the back of photo media 17, the strip being recorded on by recording head 16 of FIG. 1 or FIG. 2. The information recorded can include location, date andtime data with the location data being provided by means of keyboard input or, alternatively, through the inclusion of a positioning systems such as GPS or the like. FIG. 4 shows the back of the image 17 on which is also recorded an encoded form 22 ofthe audio information. The format of the encoding can be any form within the knowledge of the person skilled in the art. However, preferably the encoding provides a highly fault tolerant form of encoding to tolerate errors that may arise due to use andhandling of the print media. The encoding format can be, for example, Reed-Solomon encoding of the data to provide for a high degree of fault tolerance.

Turning to FIG. 4, when it is desired to "play back" the recorded audio, the photo 17 is passed through a reader device 26 which includes pinch rollers for guiding the photo 17 past a magnetic sensor device 27.

Referring now to FIG. 5, there is illustrated in schematic form the operation of the audio reader device 26 of FIG. 5. The magnetic sensor 27 is interconnected to a second Artcam central processor (ACP) 28 which is suitably adapted to read anddecode the data stored on the back of the photograph. The decoded audio information is stored in memory 32 for playback via a sound processing chip 35 on speaker 29. The sound processing chip 35 can operate under the control of the ACP decoder 28 whichin turn operates under the control of various user input controls 33 which can include volume controls, rewind, play and fast forward controls etc.

It can be seen from the foregoing description of the preferred embodiment that there is provided a system for the automatic recording of audio associated with an output image so as to provide an audio record associated with a photograph printedon ink jet media. There is also disclosed an audio reader system for reading an image recorded on the back of such a photograph.

It would be appreciated by a person skilled in the art that numerous variations and/or modifications any be made to the present invention as shown in the specific embodiment without departing from the spirit or scope of the invention as broadlydescribed. For example, the utilisation of more complex audio recording and playback techniques such as stereo and B-format techniques. The present embodiment is, therefore, to be considered in all respects to be illustrative and not restrictive.

Ink Jet Technologies

The embodiments of the invention use an ink jet printer type device. Of course many different devices could be used. However presently popular ink jet printing technologies are unlikely to be suitable.

The most significant problem with thermal ink jet is power consumption. This is approximately 100 times that required for high speed, and stems from the energy-inefficient means of drop ejection. This involves the rapid boiling of water toproduce a vapor bubble which expels the ink. Water has a very high heat capacity, and must be superheated in thermal ink jet applications. This leads to an efficiency of around 0.02%, from electricity input to drop momentum (and increased surface area)out.

The most significant problem with piezoelectric ink jet is size and cost. Piezoelectric crystals have a very small deflection at reasonable drive voltages, and therefore require a large area for each nozzle. Also, each piezoelectric actuatormust be connected to its drive circuit on a separate substrate. This is not a significant problem at the current limit of around 300 nozzles per print head, but is a major impediment to the fabrication of pagewide print heads with 19,200 nozzles.

Ideally, the ink jet technologies used meet the stringent requirements of in-camera digital color printing and other high quality, high speed, low cost printing applications. To meet the requirements of digital photography, new ink jettechnologies have been created. The target features include:

low power (less than 10 Watts)

high resolution capability (1,600 dpi or more)

photographic quality output

low manufacturing cost

small size (pagewidth times minimum cross section)

high speed (<2 seconds per page).

All of these features can be met or exceeded by the ink jet systems described below with differing levels of difficulty. 45 different ink jet technologies have been developed by the Assignee to give a wide range of choices for high volumemanufacture. These technologies form part of separate applications assigned to the present Assignee as set out in the table below.

The ink jet designs shown here are suitable for a wide range of digital printing systems, from battery powered one-time use digital cameras, through to desktop and network printers, and through to commercial printing systems.

For ease of manufacture using standard process equipment, the print head is designed to be a monolithic 0.5 micron CMOS chip with MEMS post processing. For color photographic applications, the print head is 100 mm long, with a width whichdepends upon the ink jet type. The smallest print head designed is IJ38, which is 0.35 mm wide, giving a chip area of 35 square mm. The print heads each contain 19,200 nozzles plus data and control circuitry.

Ink is supplied to the back of the print head by injection molded plastic ink channels. The molding requires 50 micron features, which can be created using a lithographically micromachined insert in a standard injection molding tool. Ink flowsthrough holes etched through the wafer to the nozzle chambers fabricated on the front surface of the wafer. The print head is connected to the camera circuitry by tape automated bonding.

Tables of Drop-on-Demand Ink Jets

Eleven important characteristics of the fundamental operation of individual ink jet nozzles have been identified. These characteristics are largely orthogonal, and so can be elucidated as an eleven dimensional matrix. Most of the eleven axesof this matrix include entries developed by the present assignee.

The following tables form the axes of an eleven dimensional table of ink jet types.

Actuator mechanism (18 types)

Basic operation mode (7 types)

Auxiliary mechanism (8 types)

Actuator amplification or modification method (17 types)

Actuator motion (19 types)

Nozzle refill method (4 types)

Method of restricting back-flow through inlet (10 types)

Nozzle clearing method (9 types)

Nozzle plate construction (9 types)

Drop ejection direction (5 types)

Ink type (7 types)

The complete eleven dimensional table represented by these axes contains 36.9 billion possible configurations of ink jet nozzle. While not all of the possible combinations result in a viable ink jet technology, many million configurations areviable. It is clearly impractical to elucidate all of the possible configurations. Instead, certain ink jet types have been investigated in detail. These are designated IJ01 to IJ45 above.

Other ink jet configurations can readily be derived from these 45 examples by substituting alternative configurations along one or more of the 11 axes. Most of the IJ01 to IJ45 examples can be made into ink jet print heads with characteristicssuperior to any currently available ink jet technology.

Where there are prior art examples known to the inventor, one or more of these examples are listed in the examples column of the tables below. The IJ01 to IJ45 series are also listed in the examples column. In some cases, a printer may belisted more than once in a table, where it shares characteristics with more than one entry.

The information associated with the aforementioned 11 dimensional matrix are set out in the following tables.

TABLE-US-00001 ACTUATOR MECHANISM (APPLIED ONLY TO SELECTED INK DROPS) Description Advantages Disadvantages Examples Thermal An electrothermal Large force High power Canon Bubblejet bubble heater heats the ink to generated Ink carrier 1979 Endoet al GB above boiling point, Simple limited to water patent 2,007,162 transferring significant construction Low efficiency Xerox heater-in- heat to the aqueous No moving parts High pit 1990 Hawkins et ink. A bubble Fast operation temperatures al U.S. Pat. No. 4,899,181 nucleates and quickly Small chip area required Hewlett-Packard forms, expelling the required for actuator High mechanical TIJ 1982 Vaught et ink. stress al U.S. Pat. No. 4,490,728 The efficiency of the Unusual process is low, withmaterials required typically less than Large drive 0.05% of the electrical transistors energy being Cavitation causes transformed into actuator failure kinetic energy of the Kogation reduces drop. bubble formation Large print heads are difficult tofabricate Piezo- A piezoelectric crystal Low power Very large area Kyser et al U.S. Pat. No. electric such as lead consumption required for actuator 3,946,398 lanthanum zirconate Many ink types Difficult to Zoltan U.S. Pat. No. (PZT) is electricallycan be used integrate with 3,683,212 activated, and either Fast operation electronics 1973 Stemme expands, shears, or High efficiency High voltage U.S. Pat. No. 3,747,120 bends to apply drive transistors Epson Stylus pressure to the ink, requiredTektronix ejecting drops. Full pagewidth IJ04 print heads impractical due to actuator size Requires electrical poling in high field strengths during manufacture Electro- An electric field is Low power Low maximum Seiko Epson, strictive used to activateconsumption strain (approx. Usui et all JP electrostriction in Many ink types 0.01%) 253401/96 relaxor materials such can be used Large area IJ04 as lead lanthanum Low thermal required for actuator zirconate titanate expansion due to low strain (PLZT) orlead Electric field Response speed magnesium niobate strength required is marginal (~10 .mu.s) (PMN). (approx. 3.5 V/.mu.m) High voltage can be generated drive transistors without difficulty required Does not require Full pagewidth electrical polingprint heads impractical due to actuator size Ferro- An electric field is Low power Difficult to IJ04 electric used to induce a phase consumption integrate with transition between the Many ink types electronics antiferroelectric (AFE) can be used Unusualand ferroelectric (FE) Fast operation materials such as phase. Perovskite (<1 .mu.s) PLZSnT are materials such as tin Relatively high required modified lead longitudinal strain Actuators require lanthanum zirconate High efficiency a large areatitanate (PLZSnT) Electric field exhibit large strains of strength of around 3 V/.mu.m up to 1% associated can be readily with the AFE to FE provided phase transition. Electro- Conductive plates are Low power Difficult to IJ02, IJ04 static platesseparated by a consumption operate electrostatic compressible or fluid Many ink types devices in an dielectric (usually air). can be used aqueous Upon application of a Fast operation environment voltage, the plates The electrostatic attract each otherand actuator will displace ink, causing normally need to be drop ejection. The separated from the conductive plates may ink be in a comb or Very large area honeycomb structure, required to achieve or stacked to increase high forces the surface area andHigh voltage therefore the force. drive transistors may be required Full pagewidth print heads are not competitive due to actuator size Electro- A strong electric field Low current High voltage 1989 Saito et al, static pull is applied to the ink,consumption required U.S. Pat. No. 4,799,068 on ink whereupon Low temperature May be damaged 1989 Miura et al, electrostatic attraction by sparks due to air U.S. Pat. No. 4,810,954 accelerates the ink breakdown Tone-jet towards the print Requiredfield medium. strength increases as the drop size decreases High voltage drive transistors required Electrostatic field attracts dust Permanent An electromagnet Low power Complex IJ07, IJ10 magnet directly attracts a consumption fabrication electro-permanent magnet, Many ink types Permanent magnetic displacing ink and can be used magnetic material causing drop ejection. Fast operation such as Neodymium Rare earth magnets High efficiency Iron Boron (NdFeB) with a field strength Easy extensionrequired. around 1 Tesla can be from single nozzles High local used. Examples are: to pagewidth print currents required Samarium Cobalt heads Copper (SaCo) and magnetic metalization should materials in the be used for long neodymium iron boronelectromigration family (NdFeB, lifetime and low NdDyFeBNb, resistivity NdDyFeB, etc) Pigmented inks are usually infeasible Operating temperature limited to the Curie temperature (around 540 K) Soft A solenoid induced a Low power Complex IJ01, IJ05,IJ08, magnetic magnetic field in a soft consumption fabrication IJ10, IJ12, IJ14, core electro- magnetic core or yoke Many ink types Materials not IJ15, IJ17 magnetic fabricated from a can be used usually present in a ferrous material such Fast operationCMOS fab such as as electroplated iron High efficiency NiFe, CoNiFe, or alloys such as CoNiFe Easy extension CoFe are required [1], CoFe, or NiFe from single nozzles High local alloys. Typically, the to pagewidth print currents required soft magneticmaterial heads Copper is in two parts, which metalization should are normally held be used for long apart by a spring. electromigration When the solenoid is lifetime and low actuated, the two parts resistivity attract, displacing the Electroplating isink. required High saturation flux density is required (2.0-2.1 T is achievable with CoNiFe [1]) Lorenz The Lorenz force Low power Force acts as a IJ06, IJ11, IJ13, force acting on a current consumption twisting motion IJ16 carrying wire in a Many inktypes Typically, only a magnetic field is can be used quarter of the utilized. Fast operation solenoid length This allows the High efficiency provides force in a magnetic field to be Easy extension useful direction supplied externally to from singlenozzles High local the print head, for to pagewidth print currents required example with rare heads Copper earth permanent metalization should magnets. be used for long Only the current electromigration carrying wire need be lifetime and low fabricatedon the print- resistivity head, simplifying Pigmented inks materials are usually requirements. infeasible Magneto- The actuator uses the Many ink types Force acts as a Fischenbeck, striction giant magnetostrictive can be used twisting motion U.S. Pat. No. 4,032,929 effect of materials Fast operation Unusual IJ25 such as Terfenol-D (an Easy extension materials such as alloy of terbium, from single nozzles Terfenol-D are dysprosium and iron to pagewidth print required developed at the Naval heads Highlocal Ordnance Laboratory, High force is currents required hence Ter-Fe-NOL). available Copper For best efficiency, the metalization should actuator should be pre- be used for long stressed to approx. 8 MPa. electromigration lifetime and lowresistivity Pre-stressing may be required Surface Ink under positive Low power Requires Silverbrook, EP tension pressure is held in a consumption supplementary force 0771 658 A2 and reduction nozzle by surface Simple to effect drop related patenttension. The surface construction separation applications tension of the ink is No unusual Requires special reduced below the materials required in ink surfactants bubble threshold, fabrication Speed may be causing the ink to High efficiency limited bysurfactant egress from the Easy extension properties nozzle. from single nozzles to pagewidth print heads Viscosity The ink viscosity is Simple Requires Silverbrook, EP reduction locally reduced to construction supplementary force 0771 658 A2 and selectwhich drops are No unusual to effect drop related patent to be ejected. A materials required in separation applications viscosity reduction can fabrication Requires special be achieved Easy extension ink viscosity electrothermally with from singlenozzles properties most inks, but special to pagewidth print High speed is inks can be engineered heads difficult to achieve for a 100:1 viscosity Requires reduction. oscillating ink pressure A high temperature difference (typically 80 degrees) isrequired Acoustic An acoustic wave is Can operate Complex drive 1993 Hadimioglu generated and without a nozzle circuitry et al, EUP 550,192 focussed upon the plate Complex 1993 Elrod et al, drop ejection region. fabrication EUP 572,220 Low efficiencyPoor control of drop position Poor control of drop volume Thermo- An actuator which Low power Efficient aqueous IJ03, IJ09, IJ17, elastic bend relies upon differential consumption operation requires a IJ18, IJ19, IJ20, actuator thermal expansion Many inktypes thermal insulator on IJ21, IJ22, IJ23, upon Joule heating is can be used the hot side IJ24, IJ27, IJ28, used. Simple planar Corrosion IJ29, IJ30, IJ31, fabrication prevention can be IJ32, IJ33, IJ34, Small chip area difficult IJ35, IJ36, IJ37,required for each Pigmented inks IJ38, IJ39, IJ40, actuator may be infeasible, IJ41 Fast operation as pigment particles High efficiency may jam the bend CMOS actuator compatible voltages and currents Standard MEMS processes can be used Easy extension

from single nozzles to pagewidth print heads High CTE A material with a very High force can Requires special IJ09, IJ17, IJ18, thermo- high coefficient of be generated material (e.g. PTFE) IJ20, IJ21, IJ22, elastic thermal expansion Threemethods of Requires a PTFE IJ23, IJ24, IJ27, actuator (CTE) such as PTFE deposition are deposition process, IJ28, IJ29, IJ30, polytetrafluoroethylene under development: which is not yet IJ31, IJ42, IJ43, (PTFE) is used. As chemical vapor standard inULSI IJ44 high CTE materials deposition (CVD), fabs are usually non- spin coating, and PTFE deposition conductive, a heater evaporation cannot be followed fabricated from a PTFE is a with high conductive material is candidate for low temperature (aboveincorporated. A 50 .mu.m dielectric constant 350.degree. C.) processing long PTFE bend insulation in ULSI Pigmented inks actuator with Very low power may be infeasible, polysilicon heater and consumption as pigment particles 15 mW power input Many inktypes may jam the bend can provide 180 .mu.N can be used actuator force and 10 .mu.m Simple planar deflection. Actuator fabrication motions include: Small chip area Bend required for each Push actuator Buckle Fast operation Rotate High efficiency CMOScompatible voltages and currents Easy extension from single nozzles to pagewidth print heads Conductive A polymer with a high High force can Requires special IJ24 polymer coefficient of thermal be generated materials thermo- expansion (such as Very lowpower development (High elastic PTFE) is doped with consumption CTE conductive actuator conducting substances Many ink types polymer) to increase its can be used Requires a PTFE conductivity to about 3 Simple planar deposition process, orders ofmagnitude fabrication which is not yet below that of copper. Small chip area standard in ULSI The conducting required for each fabs polymer expands actuator PTFE deposition when resistively Fast operation cannot be followed heated. High efficiency withhigh Examples of CMOS temperature (above conducting dopants compatible voltages 350.degree. C.) processing include: and currents Evaporation and Carbon nanotubes Easy extension CVD deposition Metal fibers from single nozzles techniques cannot Conductivepolymers to pagewidth print be used such as doped heads Pigmented inks polythiophene may be infeasible, Carbon granules as pigment particles may jam the bend actuator Shape A shape memory alloy High force is Fatigue limits IJ26 memory such as TiNi (alsoavailable (stresses maximum number alloy known as Nitinol - of hundreds of MPa) of cycles Nickel Titanium alloy Large strain is Low strain (1%) developed at the Naval available (more than is required to extend Ordnance Laboratory) 3%) fatigue resistanceis thermally switched High corrosion Cycle rate between its weak resistance limited by heat martensitic state and Simple removal its high stiffness construction Requires unusual austenic state. The Easy extension materials (TiNi) shape of the actuatorfrom single nozzles The latent heat of in its martensitic state to pagewidth print transformation must is deformed relative to heads be provided the austenic shape. Low voltage High current The shape change operation operation causes ejection of aRequires pre- drop. stressing to distort the martensitic state Linear Linear magnetic Linear Magnetic Requires unusual IJ12 Magnetic actuators include the actuators can be semiconductor Actuator Linear Induction constructed with materials such asActuator (LIA), Linear high thrust, long soft magnetic alloys Permanent Magnet travel, and high (e.g. CoNiFe) Synchronous Actuator efficiency using Some varieties (LPMSA), Linear planar also require Reluctance semiconductor permanent magnetic SynchronousActuator fabrication materials such as (LRSA), Linear techniques Neodymium iron Switched Reluctance Long actuator boron (NdFeB) Actuator (LSRA), and travel is available Requires the Linear Stepper Medium force is complex multi- Actuator (LSA). availablephase drive circuitry Low voltage High current operation operation

TABLE-US-00002 BASIC OPERATION MODE Description Advantages Disadvantages Examples Actuator This is the simplest Simple operation Drop repetition Thermal ink jet directly mode of operation: the No external rate is usually Piezoelectric ink pushesink actuator directly fields required limited to around 10 kHz. jet supplies sufficient Satellite drops However, this IJ01, IJ02, IJ03, kinetic energy to expel can be avoided if is not fundamental IJ04, IJ05, IJ06, the drop. The drop drop velocity isless to the method, but is IJ07, IJ09, IJ11, must have a sufficient than 4 m/s related to the refill IJ12, IJ14, IJ16, velocity to overcome Can be efficient, method normally IJ20, IJ22, IJ23, the surface tension. depending upon the used IJ24, IJ25,IJ26, actuator used All of the drop IJ27, IJ28, IJ29, kinetic energy must IJ30, IJ31, IJ32, be provided by the IJ33, IJ34, IJ35, actuator IJ36, IJ37, IJ38, Satellite drops IJ39, IJ40, IJ41, usually form if drop IJ42, IJ43, IJ44 velocity is greater than4.5 m/s Proximity The drops to be Very simple print Requires close Silverbrook, EP printed are selected by head fabrication can proximity between 0771 658 A2 and some manner (e.g. be used the print head and related patent thermally induced The drop theprint media or applications surface tension selection means transfer roller reduction of does not need to May require two pressurized ink). provide the energy print heads printing Selected drops are required to separate alternate rows of the separatedfrom the ink the drop from the image in the nozzle by nozzle Monolithic color contact with the print print heads are medium or a transfer difficult roller. Electro- The drops to be Very simple print Requires very Silverbrook, EP static printed areselected by head fabrication can high electrostatic 0771 658 A2 and pull on ink some manner (e.g. be used field related patent thermally induced The drop Electrostatic field applications surface tension selection means for small nozzle Tone-Jet reductionof does not need to sizes is above air pressurized ink). provide the energy breakdown Selected drops are required to separate Electrostatic field separated from the ink the drop from the may attract dust in the nozzle by a nozzle strong electric field. Magnetic The drops to be Very simple print Requires Silverbrook, EP pull on ink printed are selected by head fabrication can magnetic ink 0771 658 A2 and some manner (e.g. be used Ink colors other related patent thermally induced The drop than black areapplications surface tension selection means difficult reduction of does not need to Requires very pressurized ink). provide the energy high magnetic fields Selected drops are required to separate separated from the ink the drop from the in the nozzleby a nozzle strong magnetic field acting on the magnetic ink. Shutter The actuator moves a High speed (>50 kHz) Moving parts are IJ13, IJ17, IJ21 shutter to block ink operation can required flow to the nozzle. The be achieved due to Requires ink inkpressure is pulsed reduced refill time pressure modulator at a multiple of the Drop timing can Friction and wear drop ejection be very accurate must be considered frequency. The actuator Stiction is energy can be very possible low Shuttered The actuatormoves a Actuators with Moving parts are IJ08, IJ15, IJ18, grill shutter to block ink small travel can be required IJ19 flow through a grill to used Requires ink the nozzle. The shutter Actuators with pressure modulator movement need only small force canbe Friction and wear be equal to the width used must be considered of the grill holes. High speed (>50 kHz) Stiction is operation can possible be achieved Pulsed A pulsed magnetic Extremely low Requires an IJ10 magnetic field attracts an `ink energyoperation is external pulsed pull on ink pusher` at the drop possible magnetic field pusher ejection frequency. An No heat Requires special actuator controls a dissipation materials for both catch, which prevents problems the actuator and the the inkpusher from ink pusher moving when a drop is Complex not to be ejected. construction

TABLE-US-00003 AUXILIARY MECHANISM (APPLIED TO ALL NOZZLES) Description Advantages Disadvantages Examples None The actuator directly Simplicity of Drop ejection Most ink jets, fires the ink drop, and construction energy must be including thereis no external Simplicity of supplied by piezoelectric and field or other operation individual nozzle thermal bubble. mechanism required. Small physical actuator IJ01, IJ02, IJ03, size IJ04, IJ05, IJ07, IJ09, IJ11, IJ12, IJ14, IJ20, IJ22, IJ23, IJ24,IJ25, IJ26, IJ27, IJ28, IJ29, IJ30, IJ31, IJ32, IJ33, IJ34, IJ35, IJ36, IJ37, IJ38, IJ39, IJ40, IJ41, IJ42, IJ43, IJ44 Oscillating The ink pressure Oscillating ink Requires external Silverbrook, EP ink pressure oscillates, providing pressure can provideink pressure 0771 658 A2 and (including much of the drop a refill pulse, oscillator related patent acoustic ejection energy. The allowing higher Ink pressure applications stimulation) actuator selects which operating speed phase and amplitude IJ08,IJ13, IJ15, drops are to be fired The actuators must be carefully IJ17, IJ18, IJ19, by selectively may operate with controlled IJ21 blocking or enabling much lower energy Acoustic nozzles. The ink Acoustic lenses reflections in the ink pressureoscillation can be used to focus chamber must be may be achieved by the sound on the designed for vibrating the print nozzles head, or preferably by an actuator in the ink supply. Media The print head is Low power Precision Silverbrook, EP proximityplaced in close High accuracy assembly required 0771 658 A2 and proximity to the print Simple print head Paper fibers may related patent medium. Selected construction cause problems applications drops protrude from Cannot print on the print head furtherrough substrates than unselected drops, and contact the print medium. The drop soaks into the medium fast enough to cause drop separation. Transfer Drops are printed to a High accuracy Bulky Silverbrook, EP roller transfer roller instead Wide range ofExpensive 0771 658 A2 and of straight to the print print substrates can Complex related patent medium. A transfer be used construction applications roller can also be used Ink can be dried Tektronix hot for proximity drop on the transfer roller meltpiezoelectric separation. ink jet Any of the IJ series Electro- An electric field is Low power Field strength Silverbrook, EP static used to accelerate Simple print head required for 0771 658 A2 and selected drops towards construction separation ofsmall related patent the print medium. drops is near or applications above air Tone-Jet breakdown Direct A magnetic field is Low power Requires Silverbrook, EP magnetic used to accelerate Simple print head magnetic ink 0771 658 A2 and field selecteddrops of construction Requires strong related patent magnetic ink towards magnetic field applications the print medium. Cross The print head is Does not require Requires external IJ06, IJ16 magnetic placed in a constant magnetic materials magnet fieldmagnetic field. The to be integrated in Current densities Lorenz force in a the print head may be high, current carrying wire manufacturing resulting in is used to move the process electromigration actuator. problems Pulsed A pulsed magnetic Very lowpower Complex print IJ10 magnetic field is used to operation is possible head construction field cyclically attract a Small print head Magnetic paddle, which pushes size materials required in on the ink. A small print head actuator moves a catch, whichselectively prevents the paddle from moving.

TABLE-US-00004 ACTUATOR AMPLIFICATION OR MODIFICATION METHOD Description Advantages Disadvantages Examples None No actuator Operational Many actuator Thermal Bubble mechanical simplicity mechanisms have Ink jet amplification is used. insufficient travel, IJ01, IJ02, IJ06, The actuator directly or insufficient force, IJ07, IJ16, IJ25, drives the drop to efficiently drive IJ26 ejection process. the drop ejection process Differential An actuator material Provides greater High stressesare Piezoelectric expansion expands more on one travel in a reduced involved IJ03, IJ09, IJ17, bend side than on the other. print head area Care must be IJ18, IJ19, IJ20, actuator The expansion may be taken that the IJ21, IJ22, IJ23, thermal,piezoelectric, materials do not IJ24, IJ27, IJ29, magnetostrictive, or delaminate IJ30, IJ31, IJ32, other mechanism. The Residual bend IJ33, IJ34, IJ35, bend actuator converts resulting from high IJ36, IJ37, IJ38, a high force low travel temperature orhigh IJ39, IJ42, IJ43, actuator mechanism to stress during IJ44 high travel, lower formation force mechanism. Transient A trilayer bend Very good High stresses are IJ40, IJ41 bend actuator where the two temperature stability involved actuator outsidelayers are High speed, as a Care must be identical. This cancels new drop can be taken that the bend due to ambient fired before heat materials do not temperature and dissipates delaminate residual stress. The Cancels residual actuator only respondsstress of formation to transient heating of one side or the other. Reverse The actuator loads a Better coupling Fabrication IJ05, IJ11 spring spring. When the to the ink complexity actuator is turned off, High stress in the the spring releases. springThis can reverse the force/distance curve of the actuator to make it compatible with the force/time requirements of the drop ejection. Actuator A series of thin Increased travel Increased Some stack actuators are stacked. Reduced drive fabricationpiezoelectric ink jets This can be voltage complexity IJ04 appropriate where Increased actuators require high possibility of short electric field strength, circuits due to such as electrostatic pinholes and piezoelectric actuators. Multiple Multiplesmaller Increases the Actuator forces IJ12, IJ13, IJ18, actuators actuators are used force available from may not add IJ20, IJ22, IJ28, simultaneously to an actuator linearly, reducing IJ42, IJ43 move the ink. Each Multiple efficiency actuator needprovide actuators can be only a portion of the positioned to control force required. ink flow accurately Linear A linear spring is used Matches low Requires print IJ15 Spring to transform a motion travel actuator with head area for the with small traveland higher travel spring high force into a requirements longer travel, lower Non-contact force motion. method of motion transformation Coiled A bend actuator is Increases travel Generally IJ17, IJ21, IJ34, actuator coiled to provide Reduces chiprestricted to planar IJ35 greater travel in a area implementations reduced chip area. Planar due to extreme implementations are fabrication difficulty relatively easy to in other orientations. fabricate. Flexure A bend actuator has a Simple means ofCare must be IJ10, IJ19, IJ33 bend small region near the increasing travel of taken not to exceed actuator fixture point, which a bend actuator the elastic limit in flexes much more the flexure area readily than the Stress remainder of the distributionis very actuator. The actuator uneven flexing is effectively Difficult to converted from an accurately model even coiling to an with finite element angular bend, resulting analysis in greater travel of the actuator tip. Catch The actuator controls aVery low Complex IJ10 small catch. The catch actuator energy construction either enables or Very small Requires external disables movement of actuator size force an ink pusher that is Unsuitable for controlled in a bulk pigmented inks manner. GearsGears can be used to Low force, low Moving parts are IJ13 increase travel at the travel actuators can required expense of duration. be used Several actuator Circular gears, rack Can be fabricated cycles are required and pinion, ratchets, using standardMore complex and other gearing surface MEMS drive electronics methods can be used. processes Complex construction Friction, friction, and wear are possible Buckle plate A buckle plate can be Very fast Must stay within S. Hirata et al, used to change aslow movement elastic limits of the "An Ink-jet Head actuator into a fast achievable materials for long Using Diaphragm motion. It can also device life Microactuator", convert a high force, High stresses Proc. IEEE MEMS, low travel actuator involvedFebruary 1996, pp 418-423. into a high travel, Generally high IJ18, IJ27 medium force motion. power requirement Tapered A tapered magnetic Linearizes the Complex IJ14 magnetic pole can increase magnetic construction pole travel at the expenseforce/distance curve of force. Lever A lever and fulcrum is Matches low High stress IJ32, IJ36, IJ37 used to transform a travel actuator with around the fulcrum motion with small higher travel travel and high force requirements into a motion withFulcrum area has longer travel and no linear movement, lower force. The lever and can be used for can also reverse the a fluid seal direction of travel. Rotary The actuator is High mechanical Complex IJ28 impeller connected to a rotary advantageconstruction impeller. A small The ratio of force Unsuitable for angular deflection of to travel of the pigmented inks the actuator results in actuator can be a rotation of the matched to the impeller vanes, which nozzle requirements push the inkagainst by varying the stationary vanes and number of impeller out of the nozzle. vanes Acoustic A refractive or No moving parts Large area 1993 Hadimioglu lens diffractive (e.g. zone required et al, EUP 550,192 plate) acoustic lens is Only relevant for1993 Elrod et al, used to concentrate acoustic ink jets EUP 572,220 sound waves. Sharp A sharp point is used Simple Difficult to Tone-jet conductive to concentrate an construction fabricate using point electrostatic field. standard VLSI processes for asurface ejecting ink- jet Only relevant for electrostatic ink jets

TABLE-US-00005 ACTUATOR MOTION Description Advantages Disadvantages Examples Volume The volume of the Simple High energy is Hewlett-Packard expansion actuator changes, construction in the typically required to Thermal Ink jet pushing the ink inall case of thermal ink achieve volume Canon Bubblejet directions. jet expansion. This leads to thermal stress, cavitation, and kogation in thermal ink jet implementations Linear, The actuator moves in Efficient High fabrication IJ01, IJ02, IJ04,normal to a direction normal to coupling to ink complexity may be IJ07, IJ11, IJ14 chip surface the print head surface. drops ejected required to achieve The nozzle is typically normal to the perpendicular in the line of surface motion movement. Parallel to The actuator moves Suitable for Fabrication IJ12, IJ13, IJ15, chip surface parallel to the print planar fabrication complexity IJ33,, IJ34, IJ35, head surface. Drop Friction IJ36 ejection may still be Stiction normal to the surface. Membrane An actuator with a The effective Fabrication 1982 Howkins push high force but small area of the actuator complexity U.S. Pat. No. 4,459,601 area is used to push a becomes the Actuator size stiff membrane that is membrane area Difficulty of incontact with the ink. integration in a VLSI process Rotary The actuator causes Rotary levers Device IJ05, IJ08, IJ13, the rotation of some may be used to complexity IJ28 element, such a grill or increase travel May have impeller Small chip area frictionat a pivot requirements point Bend The actuator bends A very small Requires the 1970 Kyser et al when energized. This change in actuator to be made U.S. Pat. No. 3,946,398 may be due to dimensions can be from at least two 1973 Stemme differentialthermal converted to a large distinct layers, or to U.S. Pat. No. 3,747,120 expansion, motion. have a thermal IJ03, IJ09, IJ10, piezoelectric difference across the IJ19, IJ23, IJ24, expansion, actuator IJ25, IJ29, IJ30, magnetostriction, or IJ31,IJ33, IJ34, other form of relative IJ35 dimensional change. Swivel The actuator swivels Allows operation Inefficient IJ06 around a central pivot. where the net linear coupling to the ink This motion is suitable force on the paddle motion where thereare is zero opposite forces Small chip area applied to opposite requirements sides of the paddle, e.g. Lorenz force. Straighten The actuator is Can be used with Requires careful IJ26, IJ32 normally bent, and shape memory balance of stresses straightenswhen alloys where the to ensure that the energized. austenic phase is quiescent bend is planar accurate Double The actuator bends in One actuator can Difficult to make IJ36, IJ37, IJ38 bend one direction when be used to power the drops ejected by oneelement is two nozzles. both bend directions energized, and bends Reduced chip identical. the other way when size. A small another element is Not sensitive to efficiency loss energized. ambient temperature compared to equivalent single bendactuators. Shear Energizing the Can increase the Not readily 1985 Fishbeck actuator causes a shear effective travel of applicable to other U.S. Pat. No. 4,584,590 motion in the actuator piezoelectric actuator material. actuators mechanisms Radialconstriction The actuator squeezes Relatively easy High force 1970 Zoltan U.S. Pat. No. an ink reservoir, to fabricate single required 3,683,212 forcing ink from a nozzles from glass Inefficient constricted nozzle. tubing as Difficult to macroscopicintegrate with VLSI structures processes Coil/uncoil A coiled actuator Easy to fabricate Difficult to IJ17, IJ21, IJ34, uncoils or coils more as a planar VLSI fabricate for non- IJ35 tightly. The motion of process planar devices the free end of theSmall area Poor out-of-plane actuator ejects the ink. required, therefore stiffness low cost Bow The actuator bows (or Can increase the Maximum travel IJ16, IJ18, IJ27 buckles) in the middle speed of travel is constrained when energized. MechanicallyHigh force rigid required Push-Pull Two actuators control The structure is Not readily IJ18 a shutter. One actuator pinned at both ends, suitable for ink jets pulls the shutter, and so has a high out-of- which directly push the other pushes it. planerigidity the ink Curl A set of actuators curl Good fluid flow Design IJ20, IJ42 inwards inwards to reduce the to the region behind complexity volume of ink that the actuator they enclose. increases efficiency Curl A set of actuators curl Relativelysimple Relatively large IJ43 outwards outwards, pressurizing construction chip area ink in a chamber surrounding the actuators, and expelling ink from a nozzle in the chamber. Iris Multiple vanes enclose High efficiency High fabrication IJ22 a volume ofink. These Small chip area complexity simultaneously rotate, Not suitable for reducing the volume pigmented inks between the vanes. Acoustic The actuator vibrates The actuator can Large area 1993 Hadimioglu vibration at a high frequency. be physicallydistant required for et al, EUP 550,192 from the ink efficient operation 1993 Elrod et al, at useful frequencies EUP 572,220 Acoustic coupling and crosstalk Complex drive circuitry Poor control of drop volume and position None In various ink jet Nomoving parts Various other Silverbrook, EP designs the actuator tradeoffs are 0771 658 A2 and does not move. required to related patent eliminate moving applications parts Tone-jet

TABLE-US-00006 NOZZLE REFILL METHOD Description Advantages Disadvantages Examples Surface This is the normal way Fabrication Low speed Thermal ink jet tension that ink jets are simplicity Surface tension Piezoelectric ink refilled. After theOperational force relatively jet actuator is energized, simplicity small compared to IJ01-IJ07, IJ10-IJ14, it typically returns actuator force IJ16, IJ20, rapidly to its normal Long refill time IJ22-IJ45 position. This rapid usually dominates returnsucks in air the total repetition through the nozzle rate opening. The ink surface tension at the nozzle then exerts a small force restoring the meniscus to a minimum area. This force refills the nozzle. Shuttered Ink to the nozzle High speed RequiresIJ08, IJ13, IJ15, oscillating chamber is provided at Low actuator common ink IJ17, IJ18, IJ19, ink pressure a pressure that energy, as the pressure oscillator IJ21 oscillates at twice the actuator need only May not be drop ejection open or close thesuitable for frequency. When a shutter, instead of pigmented inks drop is to be ejected, ejecting the ink drop the shutter is opened for 3 half cycles: drop ejection, actuator return, and refill. The shutter is then closed to prevent the nozzle chamberemptying during the next negative pressure cycle. Refill After the main High speed, as Requires two IJ09 actuator actuator has ejected a the nozzle is independent drop a second (refill) actively refilled actuators per nozzle actuator is energized. Therefill actuator pushes ink into the nozzle chamber. The refill actuator returns slowly, to prevent its return from emptying the chamber again. Positive ink The ink is held a slight High refill rate, Surface spill Silverbrook, EP pressure positivepressure. therefore a high must be prevented 0771 658 A2 and After the ink drop is drop repetition rate Highly related patent ejected, the nozzle is possible hydrophobic print applications chamber fills quickly head surfaces are Alternative for:, assurface tension and required IJ01-IJ07, IJ10-IJ14, ink pressure both IJ16, IJ20, IJ22-IJ45 operate to refill the nozzle.

TABLE-US-00007 METHOD OF RESTRICTING BACK-FLOW THROUGH INLET Description Advantages Disadvantages Examples Long inlet The ink inlet channel Design simplicity Restricts refill Thermal ink jet channel to the nozzle chamber Operational ratePiezoelectric ink is made long and simplicity May result in a jet relatively narrow, Reduces relatively large chip IJ42, IJ43 relying on viscous crosstalk area drag to reduce inlet Only partially back-flow. effective Positive ink The ink is under a Dropselection Requires a Silverbrook, EP pressure positive pressure, so and separation method (such as a 0771 658 A2 and that in the quiescent forces can be nozzle rim or related patent state some of the ink reduced effective applications drop alreadyprotrudes Fast refill time hydrophobizing, or Possible from the nozzle. both) to prevent operation of the This reduces the flooding of the following: IJ01-IJ07, pressure in the nozzle ejection surface of IJ09-IJ12, chamber which is the print head. IJ14, IJ16, IJ20, required to eject a IJ22,, IJ23-IJ34, certain volume of ink. IJ36-IJ41, IJ44 The reduction in chamber pressure results in a reduction in ink pushed out through the inlet. Baffle One or more baffles The refill rate is Design HP ThermalInk are placed in the inlet not as restricted as complexity Jet ink flow. When the the long inlet May increase Tektronix actuator is energized, method. fabrication piezoelectric ink jet the rapid ink Reduces complexity (e.g. movement creates crosstalkTektronix hot melt eddies which restrict Piezoelectric print the flow through the heads). inlet. The slower refill process is unrestricted, and does not result in eddies. Flexible flap In this method recently Significantly Not applicable to Canonrestricts disclosed by Canon, reduces back-flow most ink jet inlet the expanding actuator for edge-shooter configurations (bubble) pushes on a thermal ink jet Increased flexible flap that devices fabrication restricts the inlet. complexity Inelasticdeformation of polymer flap results in creep over extended use Inlet filter A filter is located Additional Restricts refill IJ04, IJ12, IJ24, between the ink inlet advantage of ink rate IJ27, IJ29, IJ30 and the nozzle filtration May result in chamber. The filter Ink filter may be complex has a multitude of fabricated with no construction small holes or slots, additional process restricting ink flow. steps The filter also removes particles which may block the nozzle. Small inlet The ink inlet channelDesign simplicity Restricts refill IJ02, IJ37, IJ44 compared to the nozzle chamber rate to nozzle has a substantially May result in a smaller cross section relatively large chip than that of the nozzle, area resulting in easier ink Only partially egressout of the effective nozzle than out of the inlet. Inlet shutter A secondary actuator Increases speed Requires separate IJ09 controls the position of of the ink-jet print refill actuator and a shutter, closing off head operation drive circuit the inkinlet when the main actuator is energized. The inlet is The method avoids the Back-flow Requires careful IJ01, IJ03, IJ05, located problem of inlet back- problem is design to minimize IJ06, IJ07, IJ10, behind the flow by arranging the eliminated thenegative IJ11, IJ14, IJ16, ink-pushing ink-pushing surface of pressure behind the IJ22, IJ23, IJ25, surface the actuator between paddle IJ28, IJ31, IJ32, the inlet and the IJ33, IJ34, IJ35, nozzle. IJ36, IJ39, IJ40, IJ41 Part of the The actuator and aSignificant Small increase in IJ07, IJ20, IJ26, actuator wall of the ink reductions in back- fabrication IJ38 moves to chamber are arranged flow can be complexity shut off the so that the motion of achieved inlet the actuator closes off Compact designsthe inlet. possible Nozzle In some configurations Ink back-flow None related to Silverbrook, EP actuator of ink jet, there is no problem is ink back-flow on 0771 658 A2 and does not expansion or eliminated actuation related patent result in ink movementof an applications back-flow actuator which may Valve-jet cause ink back-flow Tone-jet through the inlet.

TABLE-US-00008 Description Advantages Disadvantages Examples NOZZLE CLEARING METHOD Normal All of the nozzles are No added May not be Most ink jet nozzle firing fired periodically, complexity on the sufficient to systems before the ink has aprint head displace dried ink IJ01, IJ02, IJ03, chance to dry. When IJ04, IJ05, IJ06, not in use the nozzles IJ07, IJ09, IJ10, are sealed (capped) IJ11, IJ12, IJ14, against air. IJ16, IJ20, IJ22, The nozzle firing is IJ23, IJ24, IJ25, usually performedIJ26, IJ27, IJ28, during a special IJ29, IJ30, IJ31, clearing cycle, after IJ32, IJ33, IJ34, first moving the print IJ36, IJ37, IJ38, head to a cleaning IJ39, IJ40,, IJ41, station. IJ42, IJ43, IJ44,, IJ45 Extra In systems which heat Can be highlyRequires higher Silverbrook, EP power to the ink, but do not boil effective if the drive voltage for 0771 658 A2 and ink heater it under normal heater is adjacent to clearing related patent situations, nozzle the nozzle May require applications clearingcan be larger drive achieved by over- transistors powering the heater and boiling ink at the nozzle. Rapid The actuator is fired in Does not require Effectiveness May be used succession rapid succession. In extra drive circuits depends with: IJ01,IJ02, of actuator some configurations, on the print head substantially upon IJ03, IJ04, IJ05, pulses this may cause heat Can be readily the configuration of IJ06, IJ07, IJ09, build-up at the nozzle controlled and the ink jet nozzle IJ10, IJ11, IJ14,which boils the ink, initiated by digital IJ16, IJ20, IJ22, clearing the nozzle. In logic IJ23, IJ24, IJ25, other situations, it may IJ27, IJ28, IJ29, cause sufficient IJ30, IJ31, IJ32, vibrations to dislodge IJ33, IJ34, IJ36, clogged nozzles. IJ37,IJ38, IJ39, IJ40, IJ41, IJ42, IJ43, IJ44, IJ45 Extra Where an actuator is A simple Not suitable May be used power to not normally driven to solution where where there is a with: IJ03, IJ09, ink pushing the limit of its motion, applicable hard limit toIJ16, IJ20, IJ23, actuator nozzle clearing may be actuator movement IJ24, IJ25, IJ27, assisted by providing IJ29, IJ30, IJ31, an enhanced drive IJ32, IJ39, IJ40, signal to the actuator. IJ41, IJ42, IJ43, IJ44, IJ45 Acoustic An ultrasonic wave is A highnozzle High IJ08, IJ13, IJ15, resonance applied to the ink clearing capability implementation cost IJ17, IJ18, IJ19, chamber. This wave is can be achieved if system does not IJ21 of an appropriate May be already include an amplitude and implemented atvery acoustic actuator frequency to cause low cost in systems sufficient force at the which already nozzle to clear include acoustic blockages. This is actuators easiest to achieve if the ultrasonic wave is at a resonant frequency of the ink cavity. Nozzle A microfabricated Can clear Accurate Silverbrook, EP clearing plate is pushed against severely clogged mechanical 0771 658 A2 and plate the nozzles. The plate nozzles alignment is related patent has a post for every required applications nozzle. A post moves Moving parts are through each nozzle, required displacing dried ink. There is risk of damage to the nozzles Accurate fabrication is required Ink The pressure of the ink May be effective Requires May be used pressure is temporarily whereother pressure pump or with all IJ series ink pulse increased so that ink methods cannot be other pressure jets streams from all of the used actuator nozzles. This may be Expensive used in conjunction Wasteful of ink with actuator energizing. Printhead A flexible `blade` is Effective for Difficult to use if Many ink jet wiper wiped across the print planar print head print head surface is systems head surface. The surfaces non-planar or very blade is usually Low cost fragile fabricated from aRequires flexible polymer, e.g. mechanical parts rubber or synthetic Blade can wear elastomer. out in high volume print systems Separate A separate heater is Can be effective Fabrication Can be used with ink boiling provided at the nozzle where othernozzle complexity many IJ series ink heater although the normal clearing methods jets drop e-ection cannot be used mechanism does not Can be require it. The heaters implemented at no do not require additional cost in individual drive some ink jetcircuits, as many configurations nozzles can be cleared simultaneously, and no imaging is required. NOZZLE PLATE CONSTRUCTION Electro- A nozzle plate is Fabrication High Hewlett Packard formed separately fabricated simplicity temperatures and ThermalInk jet nickel from electroformed pressures are nickel, and bonded to required to bond the print head chip. nozzle plate Minimum thickness constraints Differential thermal expansion Laser Individual nozzle No masks Each hole must Canon Bubblejet ablatedor holes are ablated by an required be individually 1988 Sercel et drilled intense UV laser in a Can be quite fast formed al., SPIE, Vol. 998 polymer nozzle plate, which is Some control Special Excimer Beam typically a polymer over nozzle profileequipment required Applications, pp. such as polyimide or is possible Slow where there 76-83 polysulphone Equipment are many thousands 1993 Watanabe required is relatively of nozzles per print et al., U.S. Pat. No. low cost head 5,208,604 May producethin burrs at exit holes Silicon A separate nozzle High accuracy is Two part K. Bean, IEEE micro- plate is attainable construction Transactions on machined micromachined from High cost Electron Devices, single crystal silicon, Requires Vol. ED-25, No.10, and bonded to the precision alignment 1978, pp 1185-1195 print head wafer. Nozzles may be Xerox 1990 clogged by adhesive Hawkins et al., U.S. Pat. No. 4,899,181 Glass Fine glass capillaries No expensive Very small 1970 Zoltan U.S. Pat. No.capillaries are drawn from glass equipment required nozzle sizes are 3,683,212 tubing. This method Simple to make difficult to form has been used for single nozzles Not suited for making individual mass production nozzles, but is difficult to use forbulk manufacturing of print heads with thousands of nozzles. Monolithic, The nozzle plate is High accuracy Requires Silverbrook, EP surface deposited as a layer (<1 .mu.m) sacrificial layer 0771 658 A2 and micro- using standard VLSI Monolithic underthe nozzle related patent machined deposition techniques. Low cost plate to form the applications using VLSI Nozzles are etched in Existing nozzle chamber IJ01, IJ02, IJ04, litho- the nozzle plate using processes can be Surface may be IJ11, IJ12, IJ17,graphic VLSI lithography and used fragile to the touch IJ18, IJ20, IJ22, processes etching. IJ24, IJ27, IJ28, IJ29, IJ30, IJ31, IJ32, IJ33, IJ34, IJ36, IJ37, IJ38, IJ39, IJ40, IJ41, IJ42, IJ43, IJ44 NOZZLE CLEARING METHOD Monolithic, The nozzle plate isa High accuracy Requires long IJ03, IJ05, IJ06, etched buried etch stop in the (<1 .mu.m) etch times IJ07, IJ08, IJ09, through wafer. Nozzle Monolithic Requires a IJ10, IJ13, IJ14, substrate chambers are etched in Low cost support wafer IJ15, IJ16,IJ19, the front of the wafer, No differential IJ21, IJ23, IJ25, and the wafer is expansion IJ26 thinned from the back side. Nozzles are then etched in the etch stop layer. No nozzle Various methods have No nozzles to Difficult to Ricoh 1995 plate beentried to eliminate become clogged control drop Sekiya et al U.S. Pat. No. the nozzles entirely, to position accurately 5,412,413 prevent nozzle Crosstalk 1993 Hadimioglu clogging. These problems et al EUP 550,192 include thermal bubble 1993 Elrod etal mechanisms and EUP 572,220 acoustic lens mechanisms Trough Each drop ejector has Reduced Drop firing IJ35 a trough through manufacturing direction is sensitive which a paddle moves. complexity to wicking. There is no nozzle Monolithic plate. Nozzleslit The elimination of No nozzles to Difficult to 1989 Saito et al instead of nozzle holes and become clogged control drop U.S. Pat. No. 4,799,068 individual replacement by a slit position accurately nozzles encompassing many Crosstalk actuatorpositions problems reduces nozzle clogging, but increases crosstalk due to ink surface waves

TABLE-US-00010 INK TYPE Description Advantages Disadvantages Examples Aqueous, Water based ink which Environmentally Slow drying Most existing ink dye typically contains, friendly Corrosive jets water, dye, surfactant, No odor Bleeds on paperAll IJ series ink humectant, and May jets biocide. strikethrough Silverbrook, EP Modern ink dyes have Cockles paper 0771 658 A2 and high water-fastness, related patent light fastness applications Aqueous, Water based ink which Environmentally Slowdrying IJ02, IJ04, IJ21, pigment typically contains: friendly Corrosive IJ26, IJ27, IJ30 water, pigment, No odor Pigment may Silverbrook, EP surfactant, humectant, Reduced bleed clog nozzles 0771 658 A2 and and biocide. Reduced wicking Pigment mayrelated patent Pigments have an Reduced clog actuator applications advantage in reduced strikethrough mechanisms Piezoelectric ink- bleed, wicking and Cockles paper jets strikethrough. Thermal ink jets (with significant restrictions) Methyl MEK is ahighly Very fast drying Odorous All IJ series ink Ethyl volatile solvent used Prints on various Flammable jets Ketone for industrial printing substrates such as (MEK) on difficult surfaces metals and plastics such as aluminum cans. Alcohol Alcohol basedinks Fast drying Slight odor All IJ series ink (ethanol, 2- can be used where the Operates at sub- Flammable jets butanol, printer must operate at freezing and others) temperatures below temperatures the freezing point of Reduced paper water. An exampleof cockle this is in-camera Low cost consumer photographic printing. Phase The ink is solid at No drying time- High viscosity Tektronix hot change room temperature, and ink instantly freezes Printed ink melt piezoelectric (hot melt) is melted in theprint on the print medium typically has a ink jets head before jetting. Almost any print `waxy` feel 1989 Nowak Hot melt inks are medium can be used Printed pages U.S. Pat. No. 4,820,346 usually wax based, No paper cockle may `block` All IJ series inkwith a melting point occurs Ink temperature jets around 80.degree. C. After No wicking may be above the jetting the ink freezes occurs curie point of almost instantly upon No bleed occurs permanent magnets contacting the print No strikethrough Inkheaters medium or a transfer occurs consume power roller. Long warm-up time Oil Oil based inks are High solubility High viscosity: All IJ series ink extensively used in medium for some this is a significant jets offset printing. They dyes limitationfor use in have advantages in Does not cockle ink jets, which improved paper usually require a characteristics on Does not wick low viscosity. Some paper (especially no through paper short chain and wicking or cockle). multi-branched oils Oil solubledies and have a sufficiently pigments are required. low viscosity. Slow drying Micro- A microemulsion is a Stops ink bleed Viscosity higher All IJ series ink emulsion stable, self forming High dye than water jets emulsion of oil, water, solubility Costis slightly and surfactant. The Water, oil, and higher than water characteristic drop size amphiphilic soluble based ink is less than 100 nm, dies can be used High surfactant and is determined by Can stabilize concentration the preferred curvaturepigment required (around of the surfactant. suspensions 5%)